I found out the easy way how much a difference makes that I had a blown head gasket on my 1050. It was a new to me GT and it seemed to work just fine, but there was an oil leak. As far as I know it is all original, one owner after the son inherited it. I asked a few questions on here, and a new head gasket was recommended. I did the same thing, cleaned out the carbon, and it was like a new engine was installed. I am still trying to get the carb adjusted properly so that it idles correctly just after starting it, but keeping the RPM high works after start up. After it gets good and warm it idles fine, and runs like a champ. Clean up the carbon buildup, add a new head gasket. Made a world of difference for me.